The present invention relates to a tarpaulin support system for turning a flat bed trailer into a fully covered van and back again into an open flat bed trailer.
The present invention relates to improvement on the tarpaulin systems described and illustrated for example in U.S. Pat. No. 4,711,484 of Tuerk, issued Dec. 8, 1987, U.S. Pat. No. 4,902,064 of Tuerk et al. issued Feb. 20, 1990 and U.S. Pat. No. 5,429,408 of Henning et al. issued Jul. 4, 1995. These patents describe and illustrate tarpaulin support systems of the type that provide a plurality of rigid, roller mounted, inverted U-shaped bows which extend laterally from one side to the other of the flat bed trailer, the rollers sliding longitudinally on horizontally disposed rails on either side of the trailer. The bows are of tubular construction, often square in cross-section, and have mounted along their outer peripheries, structural members having channels to securely but releasably grip and retain peripheral portions of tarpaulin sections. The tubular bows, when carrying the tarpaulin sections, may be moved on the rails in either direction on the flat bed to collapse or extend outwardly the sections, in accordian style, to open or close the sides of the trailer. In this way, the trailer can be set up as either a fully covered trailer or an open, flatbed one.
With increasing costs of transportation, an effort has been made to consider how additional space can be provided on the flat bed portions of such trailers to maximize allowable legal width of transported cargo. The following specification teaches one such method.
In accordance with the present invention there is provided a tarpaulin support for a tarpaulin system that converts a flat bed trailer into a fully covered trailer and back again into an open flat bed trailer as desired. The support comprises an upper tubular bow of inverted U-shape to extend laterally across the trailer, each side of the bow having a lateral, downwardly-extending tubular arm. A structural member is secured to the tubular bow along its outer periphery and extends below the free ends of the arms of the tubular bow. The structural member is provided with means to secure thereto peripheral portions of tarpaulin sections for covering the trailer. A pair of planar bases are associated with the bow, one on each side, each base having roller means secured thereto for sliding movement on a different one of a corresponding rail mounted on a corresponding side of the flat bed. Corrugated plates having vertically formed corrugations are secured to each structural member below the corresponding arm and its associated base, the corrugated plates having sufficient structural strength to support the tubular bow and its structural member and associated tarpaulin sections when in position. The overall thickness of the corrugated plate between opposite surfaces is less than that of the tubular bow.
With this construction of tarpaulin support, because the tubular portion of the bow is restricted to the upper levels of the system, extra lateral space is provided on the flat bed trailer when the tarpaulin support is in covering position at the lower portions where the corrugated plates are positioned, than otherwise would be the case. The necessary structural strength for the system, in absence of the wrap-around tubing of the bows of the prior art devices, is accomplished through the use of these corrugated plates.